package com.dataStructures.queue;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Stack;
import java.util.regex.Pattern;

public class ReversePolishMultiCalc {

	/**
	 * 匹配 + - * / ( ) 运算符
	 */
	static final String SYMBOL = "\\+|-|\\*|/|\\(|\\)";

	static final String LEFT = "(";
	static final String RIGHT = ")";
	static final String ADD = "+";
	static final String MINUS = "-";
	static final String TIMES = "*";
	static final String DIVISION = "/";

	/**
	 * 加減 + -
	 */
	static final int LEVEL_01 = 1;
	/**
	 * 乘除 * /
	 */
	static final int LEVEL_02 = 2;

	/**
	 * 括号
	 */
	static final int LEVEL_HIGH = Integer.MAX_VALUE;


	static Stack<String> stack = new Stack<>();
	static List<String> data = Collections.synchronizedList(new ArrayList<String>());

	/**
	 * 去除所有空白符
	 *
	 * @param s
	 * @return
	 */
	public static String replaceAllBlank(String s) {
		// \\s+ 匹配任何空白字符，包括空格、制表符、换页符等等, 等价于[ \f\n\r\t\v]
		return s.replaceAll("\\s+", "");
	}

	/**
	 * 判断是不是数字 int double long float
	 *
	 * @param s
	 * @return
	 */
	public static boolean isNumber(String s) {
		Pattern pattern = Pattern.compile("^[-\\+]?[.\\d]*$");
		return pattern.matcher(s).matches();
	}

	/**
	 * 判断是不是运算符
	 *
	 * @param s
	 * @return
	 */
	public static boolean isSymbol(String s) {
		return s.matches(SYMBOL);
	}

	/**
	 * 匹配运算等级
	 *
	 * @param s
	 * @return
	 */
	public static int calcLevel(String s) {
		if ("+".equals(s) || "-".equals(s)) {
			return LEVEL_01;
		} else if ("*".equals(s) || "/".equals(s)) {
			return LEVEL_02;
		}
		return LEVEL_HIGH;
	}

	/**
	 * 匹配
	 *
	 * @param s
	 * @throws Exception
	 */
	public static List<String> doMatch(String s) throws Exception {
		if (s == null || "".equals(s.trim())) throw new RuntimeException("data is empty");
		if (!isNumber(s.charAt(0) + "")) throw new RuntimeException("data illeagle,start not with a number");

		s = replaceAllBlank(s);

		String each;
		int start = 0;

		for (int i = 0; i < s.length(); i++) {
			if (isSymbol(s.charAt(i) + "")) {
				each = s.charAt(i) + "";
				//栈为空，(操作符，或者 操作符优先级大于栈顶优先级 && 操作符优先级不是( )的优先级 及是 ) 不能直接入栈
				if (stack.isEmpty() || LEFT.equals(each)
						|| ((calcLevel(each) > calcLevel(stack.peek())) && calcLevel(each) < LEVEL_HIGH)) {
					stack.push(each);
				} else if (!stack.isEmpty() && calcLevel(each) <= calcLevel(stack.peek())) {
					//栈非空，操作符优先级小于等于栈顶优先级时出栈入列，直到栈为空，或者遇到了(，最后操作符入栈
					while (!stack.isEmpty() && calcLevel(each) <= calcLevel(stack.peek())) {
						if (calcLevel(stack.peek()) == LEVEL_HIGH) {
							break;
						}
						data.add(stack.pop());
					}
					stack.push(each);
				} else if (RIGHT.equals(each)) {
					// ) 操作符，依次出栈入列直到空栈或者遇到了第一个)操作符，此时)出栈
					while (!stack.isEmpty() && LEVEL_HIGH >= calcLevel(stack.peek())) {
						if (LEVEL_HIGH == calcLevel(stack.peek())) {
							stack.pop();
							break;
						}
						data.add(stack.pop());
					}
				}
				start = i;    //前一个运算符的位置
			} else if (i == s.length() - 1 || isSymbol(s.charAt(i + 1) + "")) {
				each = start == 0 ? s.substring(start, i + 1) : s.substring(start + 1, i + 1);
				if (isNumber(each)) {
					data.add(each);
					continue;
				}
				throw new RuntimeException("data not match number");
			}
		}
		//如果栈里还有元素，此时元素需要依次出栈入列，可以想象栈里剩下栈顶为/，栈底为+，应该依次出栈入列，可以直接翻转整个stack 添加到队列
		Collections.reverse(stack);
		data.addAll(new ArrayList<>(stack));

		System.out.println(data);
		return data;
	}

	/**
	 * 算出结果
	 *
	 * @param list
	 * @return
	 */
	public static Double doCalc(List<String> list) {
		Double d = 0d;
		if (list == null || list.isEmpty()) {
			return null;
		}
		if (list.size() == 1) {
			System.out.println(list);
			d = Double.valueOf(list.get(0));
			return d;
		}
		ArrayList<String> list1 = new ArrayList<>();
		for (int i = 0; i < list.size(); i++) {
			list1.add(list.get(i));
			if (isSymbol(list.get(i))) {
				Double d1 = doTheMath(list.get(i - 2), list.get(i - 1), list.get(i));
				list1.remove(i);
				list1.remove(i - 1);
				list1.set(i - 2, d1 + "");
				list1.addAll(list.subList(i + 1, list.size()));
				break;
			}
		}
		doCalc(list1);
		return d;
	}

	/**
	 * 运算
	 *
	 * @param s1
	 * @param s2
	 * @param symbol
	 * @return
	 */
	public static Double doTheMath(String s1, String s2, String symbol) {
		Double result;
		switch (symbol) {
			case ADD:
				result = Double.valueOf(s1) + Double.valueOf(s2);
				break;
			case MINUS:
				result = Double.valueOf(s1) - Double.valueOf(s2);
				break;
			case TIMES:
				result = Double.valueOf(s1) * Double.valueOf(s2);
				break;
			case DIVISION:
				result = Double.valueOf(s1) / Double.valueOf(s2);
				break;
			default:
				result = null;
		}
		return result;

	}

	public static void main(String[] args) {
		//String math = "9+(3-1)*3+10/2";
		String math = "12.8 + (2 - 3.55)*4+10/5.0";
		try {
			doCalc(doMatch(math));
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}
